anaerobic bloodstreaminfections (BSI) cause significant morbidity and mortality in adult and pediatric patients, and the incidence of anaerobic infections like Fusobacterium necrophorum is increasing worldwide. The standard of care for pediatric BSI is to obtain only aerobic cultures and to skip the anaerobic culture, as it is perceived to be a cost-saving measure. However, anaerobic bacteria cannot grow in aerobic media and facultative aerobic bacteria preferentially grow in anaerobic conditions. Decreased detection of anaerobic BSI can lead to increased morbidity, incappropriate antimicrobial therapy, and death. The goal is to evaluate the implementation of an anaerobic blood culture for each aerobic blood culture, with the primary objective of describing the prevalance of anaerobic organisms causing BSI at CHLA and to determine if appropriate treatments occur sooner for facultative organisms that grow faster in anaerobic culture. Secondary objectives include determining risk factors for an anaerobic infection and septic shock, and describing the cost of inclusion of anaerobic culture for all blood culture orders.